The present invention relates to a bipolar hemostatic forceps having a pair of electrodes at a distal end of an inserting portion to be inserted into a body cavity through an endoscope.
A monopolar high frequency treatment tool is commonly used for endoscopic surgery. The monopolar high frequency treatment tool utilizes an electrode in combination with a counter plate attached to the body surface of a patient so that high frequency current flows between the electrode and the counter plate.
In the surgery utilizing the monopolar high frequency treatment tool, electric leak may occur if the patient comes in contact with a conductor other than the counter plate, which causes decrease of current effective to the operation and/or the surgeon to get burned.
Japanese patent provisional publication No. P2000-271128 discloses a bipolar high frequency treatment tool that overcomes the disadvantages of the monopolar high frequency treatment tool. The treatment tool disclosed in the above mentioned publication has a pair of electrodes mounted at the distal end of the treatment tool. The electrodes are arranged so as to open and close like pincers by a remote manipulation from the proximal end of the treatment tool. The electrodes are connected to the positive and negative terminals of a high frequency power supply, respectively, so that high frequency current flows through the tissue of the patient pinched between the electrodes.
The treatment tool disclosed in the above-mentioned publication is designed as a biopsy forceps and the pair of electrodes provided thereto opens widely to effectively sample tissue. Therefore, if this treatment tool is utilized as a hemostatic forceps for stopping bleeding of a blood vessel, the pair of electrodes pinch not only the blood vessel but also a large portion of tissue around the blood vessel. As a result, the hemostasis of the blood vessel cannot be carried out efficiently and not only the blood vessel but also the tissue therearound get heated.
Thus, there is a need for a bipolar hemostatic forceps that is capable of pinching a bleeding portion between a pair of electrodes thereof without pinching also a large portion of tissue around the bleeding portion.